Thin‐film thickness calculation to maximize X‐ray fluorescence intensity in transmission arrangements

Equations were obtained from physical theory to express the fluorescence intensity emitted by a sample in terms of the geometrical parameters of a source–sample–detector cylindrical symmetry arrangement. These equations allow the calculation of the optimum sizes of samples in XRF. The thickness required to maximize the detected fluorescence intensity, in terms of the value of the remaining physical and geometrical parameters, was determined. A thin sample in transmission geometry was considered, where excitation is produced by an isotropic monoenergetic x‐ray source. The sizes of the detector and source are such that they are considered to be dimensionless compared with the sample. These approximations do not affect the validity of the results. Copyright © 1986 John Wiley & Sons, Ltd.